Tokyo temperatures and growth potential, animated

I made a note a couple months ago to make animated charts showing the cool-season (C₃) and warm-season (C₄) turfgrass growth potential over a 100+ year period for Tokyo. I was interested to see what those charts would look like. Here’s my note:

Animate 100 years of GP curves with shadow
do an animation in Japan of GP through the years and see
if leaving shadows show something like a shift that
implies getting better for C3 or better for C4

First I got the average monthly temperatures from Tokyo since 1875.

Then, from those temperature data, I calculated the temperature-based growth potential (GP) for cool-season grass and plotted that with a shadow.

And then I did the same for the warm-season turfgrass GP.

The code I used to make these charts is in this gist.

If you are really interested in these temperature changes, check out the chart and analysis by Ryo Nakagawara, here, which shows temperatures increased by about 3 °C in winter months and about 2 °C in summer over the past ~140 years.